| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of securing high-efficiency PM collection in normal time and hardly generating white smoke, pale smoke or pungent odor in cold starting. <P>SOLUTION: This exhaust emission control device has: a branch part 5 installed in the middle of an exhaust system 4; a plurality of branch pipes 6 and 7 disposed in parallel in the downstream of the branch part 5; and particulate filters F1 and F2 or catalysts of a plurality of exhaust emission control devices interlaid in the respective branch pipes 6 and 7. The particulate filters F1 and F2 or catalysts of the exhaust emission control devices are composed by incorporating electric heaters Fh1 and Fh2 in the upstream sides and filter bodies Ff1 and Ff2 or catalyst carriers in the downstream sides, respectively. Selector valves V1 and V2 are interlaid in respective regions of the branch pipes 6 and 7 between the branch part 5 and the particulate filters F1 and F2 or catalysts. A bypass valve Vb is interlaid in a bypass pipe B. An engine cooling water temperature detection means Tw is installed in an engine cooling system 10. Exhaust temperature detection means T1 and T2 are installed in the upstream sides of the particulate filters F1 and F2 or catalysts, respectively. <P>COPYRIGHT: (C)2003,JPO</p> |
